For improved safety, for example, demand has recently been growing for head-up displays (HUDs) that present meters showing driving data (e.g., speed information) within the driver's field of vision on the automotive windshield.
To date, various HUD systems have been developed. In one exemplary HUD, no HUD display unit is provided on the windshield surface, and information (e.g., speed information) sent from the control unit is reflected on the windshield from a display unit of the instrumental panel, so that the driver can view information on the windshield (i.e., within the driver's field of vision on the windshield). This reflection-type HUD allows, with appropriate adjustment of the focal length, the displayed information to appear distant. This eliminates the need for the driver to change the focus of his or her eyes, offering safety advantages.
Patent Literature 1 discloses a laminated glass including two transparent sheets and an interlayer therebetween, where the interlayer contains hydroxy terephthalate as a luminescent material. The laminated glass of Patent Literature 1 displays high contrast images under irradiation with light. In view of advantages of the respective HUDs, combining a HUD using such a laminated glass including a luminescent material with a reflection-type HUD has been demanded. However, since the laminated glass disclosed in Patent Literature 1 includes two parallel glass sheets, a windshield formed of such a laminated glass may cause a double image phenomenon of the meters in the driver's field of vision.